Provent 200 Question (1 Viewer)

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Oct 6, 2008
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Location
Calgary, Alberta - Canada
I just bought a Provent 200 oil/air separator, like the pic below. I got a question for members who installed/familair with this system. Is the round valve by the exit port adjustable? It is referred to in the manual/spec sheet as the "Pressure Regulator" or "Control Valve" which gives the impression that it is adjustable.

I tried to turn it but it took a super-human force to turn just 1/4 turn and then no more. I could see a small gap between the valve and the exit port (see second pic). I don't really know if it should be there, and if so, how much should I adjust it for.

I hope I didn't ruin it by forcibly trying to turn the valve..
Any suggestions??!!

Cheers,
Provent.jpg
Valve.jpg
 
I fitted one of these about 6 months back, you are not going to like what I have to say.

In stock form they are junk. If you don't need an air/oil seperator and have such low oil content in your breather then they will sit there and be okay.
If you do need oil seperation, they will not work, in fact combined with acceleration and the angles involved with off-road work they can feed your engine large gulps of oil. Potentially large enough to cause mechanical damage (hydraulic lock) and more than enough for the engine to run-away until it has sucked all the oil out of the intake.

In the short time I had mine fitted as instructed my engine consumed about 9 litres of it's own oil. It was so bad it ran on it's own oil at least 5 times, including when my wife was driving it alone and had no idea what was going on.
I seriously thought my engine needed rebuilt. I did rebuild my turbocharger, un-necessarily of course.

The problem is the vent arrangement.
Stock a provent puts oily air in the top, where it has to drain through the filter. The oil that drips out of the filter (blown by the air movement) is then spread around the lower chamber where a large proportion of it goes straight out the exit and into your intake.
Eh?

If you are offroad on an angle, the collection of oil from the filter can drop straight out and into the outlet to your intake without going down the drain.

I modified mine to work as they should have been originally. I gutted the pressure setting valve you see in the original outlet (lower port) and made this the inlet. I made some alumiminium spacers to block off the resulting holes in that cap.
I then connected the outlet to the top port.

The result now is oiley air enters the bottom and the oil has a path straight to the wall and down the drain. For air to get out the top port it has to first get centrifuged in the lower chamber and then pass through the filter element where it sheds the remainder of it's oil.
Working in this way (modified and contrary to manufacturers instructions) it works quite well as an air/oil seperator. My turbo and intake are the cleanest they have ever been and oil consumption has stopped. Luckily my engine survived ingesting this much oil.

But would I recommend people pay this much for a seperator and then modify it? Nope.
Instead get a large cheap breather can and use that. It will work just as well and not require modification.
 
To answer your original question.

That is the "self regulating" outlet valve. The intent is it closes more when intake vacuum increases to limit the airflow and stop vacuuming out the engine crankcase.
The cap isn't supposed to turn, it clicks in place and is actually two pieces.
 
Hey Cancruiser - you didn't wreck anything. I did the same thing when I first got it.

Dougal - That sucks. I've had mine on for 8k kms. Did you have yours tapped into your turbo oil feed line or have a long drain tube?
 
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Hey Cancruiser - you didn't wreck anything. I did the same thing when I first got it.

Dougal - That sucks. I've had mine on for 8k kms. Did you have yours tapped into your turbo oil feed line or have a long drain tube?

Hi Shred

I had the outlet plumbed back into my intake just before the turbo. The oil drain out the bottom headed straight into the factory barb in the sump.

The difference with my setup is the provent replaced a factory external air/oil seperator. So it's got a lot more oil flow than engines with the seperator built into the rocker cover. This is I guess the true test of an air/oil seperator.

I did 1640km with the provent installed as intended and it drank about 9 litres. To do 8,000km the way it was would have cost me 44 litres of oil.
The smoke screen it put out was truely impressive. The turbo compressor housing would fill up with oil, then when you hit enough boost it would swirl it all out and into the inlet piping. Next LH corner and it all sloshes from the piping into the intake manifold.
Boom. Engine running on it's own oil and making a hell of a racket with a huge amount of smoke. Repeat on the next LH corner.

It got a little old after a while.

With the rejigged provent (aka Brovent) it has used no oil in the same distance. It has leaked some, but that doesn't count.
 
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Ive been useing a provent 200 for over 2 years now
(80 series 1hdft auto) & it does a very good job of removing the oil from the blowby.
My intake pipe's & intercooler are always clean & dry.
Sorry i dont know if that if that cap is an adjustment.

Hamo
 
Ive been useing a provent 200 for over 2 years now
(80 series 1hdft auto) & it does a very good job of removing the oil from the blowby.
My intake pipe's & intercooler are always clean & dry.
Sorry i dont know if that if that cap is an adjustment.


Hamo

DSCF0183.jpg

DSCF0186.jpg
 
Thanks guys for the replies..

Dougal, what you are saying makes perfect sense indeed. So, per the original setup they basically managed to separate the oil and air successfully but they gave them another chance to mix again right before the air gets sucked into the intake manifold. That's not very smart of them!

I was shocked by the amount of oil that your truck consumed. Is that how much oil usually gets vented from crank case? That sounds awfully high!!

I was wondering, what happens if I reverse the inlet and outlet hoses without changing the "regulator valve" and leaving it as is. Any ideas??

Any chance of posting some pictures of your setup? That will be much appreciated..
 
Here are the pictures of the changes I made.
The oil consumption was roughly half a litre an hour, which would be roughly what I expect to go through the oil seperator. Keep in mind this engine from the factory had an external seperator, it doesn't seperate the oil in the rocker cover and leave it inside like most other engines do. It seperates it externally and drains back to a barb on the sump.

Provent on the bench. The lower hose (return to the intake) is a clear pvc hose which is black on the inside from all the oil leaving the wrong way.
attachment.php


First cover of the pressure compensating valve open:
attachment.php


The valve parts spread across the bench:
attachment.php

IMAG0102.jpg
IMAG0103.jpg
provent_valve_parts.jpg
 
I machined two aluminium blanks to seal up the cap. With black RTV to ensure a seal:
attachment.php


And here is where it is installed:
attachment.php

provent_valve_blocked.jpg
IMAG0101.jpg
 
Dougal,

Thanks for the pictures. That's some clever work you've done!

1/2 liter of oil an hour!! :eek::eek::eek: That's unbelievable!! What engine do you have in your truck||

My truck (HDJ81 with 1HD-T engine) never produce any amount close to this. I have a make-shift oil collection setup now (using one of those clear plastic fuel filters) and all I see are a few CC's of oil every oil change (5000 km). Maybe a tablespoonful at the most.

But, I do agree with you totally on how strange they risk the oil to mix up with air again before the air exists the Provent.

I did a quick test today, I left the provent as is (unaltered) and blew some air in it backwards (reversed the inlet and outlet like you did) and it seems to work fine. The only drawback is that both valves become ineffective now since they see pressure backwards (no big deal I guess, looking at your setup in which one of them was canceled totally).
I did this experiment to see if I can quickly revere the input/output hoses should any problem arises.

I will install it and report back..

Thanks again...
:cheers::cheers:
 
This is on the Isuzu 4BD1T. The difference is your 1HD-T does the oil seperation internally, this engine doesn't. It had a factory seperator which I replaced with the Provent.

I also put a small plastic deflector in the lower hose where the valve was to direct the air in a bit more. This probably isn't necessary, but it seemed like a nice touch,
 
I fitted one of these about 6 months back, you are not going to like what I have to say.

In stock form they are junk. If you don't need an air/oil seperator and have such low oil content in your breather then they will sit there and be okay.
If you do need oil seperation, they will not work, in fact combined with acceleration and the angles involved with off-road work they can feed your engine large gulps of oil. Potentially large enough to cause mechanical damage (hydraulic lock) and more than enough for the engine to run-away until it has sucked all the oil out of the intake.

In the short time I had mine fitted as instructed my engine consumed about 9 litres of it's own oil. It was so bad it ran on it's own oil at least 5 times, including when my wife was driving it alone and had no idea what was going on.
I seriously thought my engine needed rebuilt. I did rebuild my turbocharger, un-necessarily of course.

The problem is the vent arrangement.
Stock a provent puts oily air in the top, where it has to drain through the filter. The oil that drips out of the filter (blown by the air movement) is then spread around the lower chamber where a large proportion of it goes straight out the exit and into your intake.
Eh?

If you are offroad on an angle, the collection of oil from the filter can drop straight out and into the outlet to your intake without going down the drain.

I modified mine to work as they should have been originally. I gutted the pressure setting valve you see in the original outlet (lower port) and made this the inlet. I made some alumiminium spacers to block off the resulting holes in that cap.
I then connected the outlet to the top port.

The result now is oiley air enters the bottom and the oil has a path straight to the wall and down the drain. For air to get out the top port it has to first get centrifuged in the lower chamber and then pass through the filter element where it sheds the remainder of it's oil.
Working in this way (modified and contrary to manufacturers instructions) it works quite well as an air/oil seperator. My turbo and intake are the cleanest they have ever been and oil consumption has stopped. Luckily my engine survived ingesting this much oil.

But would I recommend people pay this much for a seperator and then modify it? Nope.
Instead get a large cheap breather can and use that. It will work just as well and not require modification.


Hi Dougal. This is a good video from the manufacturer in how to install the Provent. Was your oil return line at the sump level, or did you return higher and use their inline adapter for returns above the sump line? Or, with the info on the video, would this still not explain your issue. Is this simply a non issue for engines which does the oil separation internally, unlike on your Isuzu 4BD1T, as I've not heard of anyone else having this issue on this board.

Thanks for your thoughts.

gb

 
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Hi Dougal. This is a good video from the manufacturer in how to install the Provent. Was your oil return line at the sump level, or did you return higher and use their inline adapter for returns above the sump line? Or, with the info on the video, would this still not explain your issue. Is this simply a non issue for engines which does the oil separation internally, unlike on your Isuzu 4BD1T, as I've not heard of anyone else having this issue on this board.

Thanks for your thoughts.

gb

My oil return was to below sump level. It's the factory drain point for the original air/oil separator.

Honestly I think these were designed backwards. When reversed "Brovent" they actually work and cannot feed liquid oil to the intake under any circumstances. The clean air then goes out the top and all oil seperation is done down low.

Others have had issues too. Not on this board though.
 
I had problems with a Provent on my turbo H. (I suppose putting a turbo on an H was a bad enough idea on it's own ;) ) The engine suffered from real bad blowby which pressurized the crankcase quite a bite. The crankcase vapors exhausted from the side lifter cover and not the valve cover. (Lots of oil mist here.) The drain went to the sump with a 3/4" ID barb above the oil level. I never had a problem with the engine running from it's own oil but it would occasionally blow huge clouds of smoke and the air filter would be fairly saturated with oil near where the vent line entered the housing.
 
This is a good video from the manufacturer in how to install the Provent.
Thanks for posting the video, I hadn't yet looked into the proper return line configuration.

Are you guys with problems using a checkvalve on the returns?
 
Ive been useing a provent 200 for over 2 years now
(80 series 1hdft auto) & it does a very good job of removing the oil from the blowby.
My intake pipe's & intercooler are always clean & dry.
Sorry i dont know if that if that cap is an adjustment.

Hamo

UPDATE: Still no issues with my Provent 200. Over 7 years now & I have only replaced the filter once.
Id still recommend fitting a Genuine Provent 200 (Not the cheap copy)

Ham00
 
UPDATE: Still no issues with my Provent 200. Over 7 years now & I have only replaced the filter once.
Id still recommend fitting a Genuine Provent 200 (Not the cheap copy)

Ham00

Did you pipe the return line somewhere or do you drain it? I may have missed it but do you have pictures of where you installed it?
 
Did you pipe the return line somewhere or do you drain it? I may have missed it but do you have pictures of where you installed it?
I just drain whats in the return line 20 - 30 mil between oil changes.
Pics are long gone. Lost to the system..

Hamo
 

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